"Cast Away" is a laugh-out-loud delight, easily the funniest picture since "South Park." It will bring joy to audiences, though not in the way it was intended -- as an uplifting tale of the human spirit.

Instead it will bring joy in a way certainly not intended, as one of the most gloriously and unwittingly silly films ever devised by a major American filmmaker. Still, joy is joy, so even if Tom Hanks and director Robert Zemeckis ("Forrest Gump") had no idea they were making a comedy, we shouldn't hold that against them.

Bad movies are like a box of chocolates: You never know what you're going to get. This time we get Tom Hanks as a FedEx exec who becomes an inadvertent slapstick comedian after he washes up on a desert island.

Hanks had the original idea for the film, which, from an actor's point of view, had to be irresistible. What better way to go for a third Oscar than to spend most of a movie as the only human being onscreen? (He already has been nominated for a Golden Globe.) And what better way to prove one's seriousness than by losing over 50 pounds and acquiring lots of facial hair? Ninety minutes in, Hanks is hairier than a community-theater John the Baptist.

Zemeckis is a capable director, so despite the misguided concept, the movie is anything but inept. In fact, the 30 minutes that lead up to Hanks' island ordeal are well done. First of all, there's the plane crash, and what a crash it is. Chuck (Hanks) is traveling on a cargo jet. The plane hits some bumpy air. He gets up, looks around, goes into the bathroom. And a second later he is hanging sideways out of the bathroom, holding on by his fingernails.

Nervous fliers will revisit the plane crash sequence in their nightmares. It's harrowing. The plane hits the ocean and breaks up. From there, our hero struggles to get to the ocean surface, and once there, he has to contend with fuel fires while trying to avoid getting sucked into the engine. In retrospect,

Hanks' getting sucked into the engine might have made for a nifty finish. Instead, he washes up on the island, and this is where the fun starts.

For the island scenes, Zemeckis employs a novel strategy in his use of sound. He lets the island speak for itself. There's no music track, just the island noises and the ebb and flow of the ocean. Zemeckis' realistic strategy works at first, and then it backfires, creating the feel of one of those "The Making of . . ." shorts. Soon it becomes impossible to forget that we're watching a millionaire actor stumbling around, pretending to be alone while within three feet of a camera crew, a dressing room and a hot lunch.

Remember how in the old Laurel and Hardy movies, Laurel would always accidentally do something to cause Hardy physical injury -- and Hardy would always let out a painful wail? In every one of those movies, it would eventually get to the point where audiences actually looked forward to the ridiculous sound of Hardy screaming. Well, something like that happens with Hanks in "Cast Away."

Our hero cuts his thigh on a rock: "Ahhhhh!" He tries to build a fire and slices the skin off his hands: "Ahhhhh!" Or he tries to pull an infected tooth with an ice skate: "Ahhhhh!" he screams, then faints. I haven't laughed so hard in months.

"Cast Away" turns out to be a picture in which Hanks spends 45 minutes talking to a volleyball. It's a spirited relationship. You haven't lived until you've seen Hanks, covered in hair, apologizing to a volleyball. Or weeping because his volleyball-friend is missing.

Such scenes are meant to highlight Chuck's desperation. Instead they show the desperate lengths to which an actor will go in pursuit of another Oscar nomination.

Helen Hunt plays Kelly, the woman Chuck loves and hopes to see again. Hunt is down to earth, lovely and affecting, and her scenes with Hanks are the best in the picture. But the last part of the movie is so suffused in schmaltz and half-baked sad-sack philosophy that it leaves Hunt with nothing to do but stand in admiration of our hero's quiet courage and nobility.